Accidentally used NS4G restore like an *****

I found a link leading to a thread on this site's sprint nexus s 4G section which gave them a one click restore. so now my tmobile phone thinks its a sprint and obviously has no service at all. what can I do??

3. Boot into your bootloader (Press Power + Volume Up) from a powered off state. Now unlock your bootloader if you haven't already done so. Connect you device via USB cable to your computer. Open a Command Terminal Window and type in the following below.

Code:

fastboot oem unlock

4. From the bootloader screen once again Open a new Command Terminal Window and type in the following...